emacs standard-/buffer-display-table alterations (transliteration experiment)

I adapted cyril-util.el for having transliteration of the Mkhedruli script of Georgian language. A very quick and dirty hack, but it led me to trying to learn about display-tables. The function standard-display-mkhedruli-translit flips (using a buffer-local variable) between Georgian and latin alphabet by altering the buffer-display-table, or creating a new fresh one. I posted it here: https://gist.github.com/1253614

In addition to t开发者_运维技巧his, I alter the standard-display-table in .emacs to eliminate line-wrapping eol char, and making split windows on tty use a nicer (unicode) character, like this:

(set-display-table-slot standard-display-table 'wrap ?\ )
(set-display-table-slot standard-display-table 'vertical-border ?│)

The problem now is that, though transliteration works all right, I end up losing my standard-display-table adjustments. Any ideas how to bring all this together seamlessly? I wouldn't want to have these adjustments also in my mkhedruli-function...

(There are certainly a few more flaws, such as the rough (redraw-display), which I for some reason needed to do).

You can use (set-char-table-parent <newtable> standard-display-table) on the newly created table.

While I'm here: you can simplify your code by using define-minor-mode. Other kinds of simplifications:

(let ( (mkhedruli-language nil) )
  (if (equal mkhedruli-active nil)
      (setq mkhedruli-language "Georgian")
    (setq mkhedruli-language nil))
  (with-current-buffer (current-buffer)
    (if (equal mkhedruli-language nil)
        (setq mkhedruli-active nil)
      (setq mkhedruli-active t)))

turns into

(let ( (mkhedruli-language nil) )
  (setq mkhedruli-language
        (if (equal mkhedruli-active nil)
            "Georgian"
          nil))
  (if (equal mkhedruli-language nil)
      (setq mkhedruli-active nil)
    (setq mkhedruli-active t))

which can turn into

(let ((mkhedruli-language
       (if mkhedruli-active nil "Georgian"))))
  (setq mkhedruli-active 
        (if mkhedruli-language t nil))

tho you may prefer to just switch the two:

(setq mkhedruli-active (not mkhedruli-active))
(let ((mkhedruli-language
       (if mkhedruli-active "Georgian"))))

and even get rid of mkhedruli-language altogether since you only test if it's nil, and you can test mkhedruli-active instead to get the same information.